Lynch, James, author
World Bank, 1994
Buku Teks
Gross, Jean, author
Routledge: Taylor & Francis Group, 2008
Buku Teks
editors, Seamus Hegarty; Mithu Alur
Sage production , 2005
Buku Teks
edited by David Hollar
Springer, 2012
eBooks
Gargiulo, Richard M., author
Wadsworth and Cengage Learning, 2011
Buku Teks